Patent Application
20170045130
The present disclosure generally pertains to rotating shafts for machines, and is directed toward a rotating shaft including a journal with an exothermically bonded sleeve.
Rotating shafts, such as camshafts and crankshafts, for machines, such as construction and mining machines, generally include various contact features, such as journals and cams that are in constant contact with other components of the machines causing wear at the surface of the contact feature. Building contact features back up is costly and time consuming.
U.S. Pat. No. 5,536,587 to W. Whitney discloses a shaft bearing formed from an aluminum alloy. The alloy may be formed into a continuous solid strip by a quench casting operation, wherein molten alloy is fed into an interface between two internally-cooled rolls to freeze the alloy into a solid strip condition in less than one second. The aluminum alloy strip can be pressure bonded to a steel backing strip to form a composite strip useful in forming a shaft bearing.
The present disclosure is directed toward overcoming one or more of the problems discovered by the inventor.
A contact feature of a shaft for a machine is disclosed herein. In embodiments, the contact feature includes an integral portion, a sleeve, and a bond layer. The integral portion is integral to the shaft and includes a profile that is less than the overall profile of the contact feature. The sleeve is placed around the integral portion and includes the overall profile of the contact feature. The bond layer is placed between the integral portion and the sleeve. The bond layer joins at least a majority of an interface between the integral portion and the sleeve together.
A method for manufacturing a shaft for a machine is also disclosed. In embodiments, the method includes placing a sleeve around an integral portion of the shaft. The method also includes placing a reaction material between the sleeve and the integral portion. The method further includes bonding at least a majority of an interface between the integral portion and the sleeve together with the reaction material to form a contact feature of the shaft that includes the sleeve, the integral portion and a resultant bond layer there between.
The systems and methods disclosed herein include a shaft, such as a camshaft or a crankshaft, for a machine, such as a construction or a mining machine. In embodiments, the shaft includes contact features, such as journals and cams that include an integral portion and a sleeve. The integral portion is integral to a majority of the shaft, while the sleeve is bonded to the integral portion by an exothermic reaction. Bonding the sleeve to the integral portion may prevent rotation of the sleeve relative to the integral portion.
One or more of the end journals 110 may include an end journal integral portion 112, an end journal sleeve 114, and an end journal bond layer 115. The end journal integral portion 112 is integral to a majority of the camshaft 100, such as the shaft portion 105. The end journal integral portion 112 may include a cylindrical shape. The profile, such as the outer diameter, of the end journal integral portion 112 is smaller than the overall profile, such as the outer diameter, of the end journal 110. The profile of the journal integral portion 112 prior to being bonded to the end journal sleeve 114 may be offset from the overall profile of the end journal 110 by a predetermined amount, such as the thickness of the end journal sleeve 114.
End journal sleeve 114 is located outward from and surrounds the end journal integral portion 112. The end journal sleeve 114 may include a hollow cylinder shape. In the embodiment illustrated, the end journal sleeve 114 is a single integral piece formed in a hollow cylinder shape. The outer profile, such as the outer diameter, of the end journal sleeve 114 is at least as large as the desired minimum material condition of the end journal 110. Prior to being bonded to the end journal integral portion 112, the inner profile, such as the inner diameter, of the end journal sleeve 114 may be within a predetermined tolerance of the profile of the end journal integral portion 112. In some embodiments, the inner profile of the end journal sleeve 114 may be smaller than the outer profile of the end journal integral portion 112 to form an interference fit between the two prior to bonding.
The end journal sleeve 114 and the end journal integral portion 112 are joined at their interface by the end journal bond layer 115. The interface may be at the inner surface of the end journal sleeve 114 and the outer surface of the end journal integral portion 112 when the end journal sleeve 114 is located around the end journal integral portion 112 prior to forming the end journal bond layer 115.
The end journal bond layer 115 may be a metallurgical bond formed by an exothermic reaction ignited between the end journal integral portion 112 and the end journal sleeve 114. The end journal bond layer 115 metallurgically bonds at least a majority of the interface between the end journal sleeve 114 and the end journal integral portion 112 together, such as joining at least a majority of the inner surface of the end journal sleeve 114 and at least a majority of the outer surface of the end journal integral portion 112 together. The end journal bond layer 115 may include materials from the integral portion, materials from the sleeve, and residual reaction materials from the exothermic reaction that forms the end journal bond layer 115.
Inner journal sleeve 124 is located outward from and surrounds the inner journal integral portion 122. The inner journal sleeve 124 may include a hollow cylinder shape and may include multiple inner journal sleeve sections 126. In the embodiment illustrated, the inner journal sleeve 124 includes two inner journal sleeve sections 126 that are combined to form the hollow cylinder shape. The inner journal sleeve sections 126 each include two inner journal sleeve ends 128. The inner journal sleeve sections 126 may be bonded together, such as by welding or by an exothermic reaction, at their adjoining inner sleeve ends 128. In some embodiments, the bonding of the inner journal sleeve sections 126 is adjacent the outer surface of the inner journal sleeve 124 and does not penetrate to the inner journal integral portion 122. The inner journal sleeve sections 126 may be symmetrical and may be split down the center of the inner journal sleeve 124. In the embodiment illustrated, the inner sleeve ends 128 extend between the outer and inner surfaces of the inner journal sleeve 124 normal to both the outer and inner surfaces.
The outer profile, such as the outer diameter, of the inner journal sleeve 124 is at least as large as the desired minimum material condition of the inner journal 120. Prior to being bonded to the inner journal integral portion 122, the inner profile, such as the inner diameter, of the inner journal sleeve 124 may be within a predetermined tolerance of the profile of the inner journal integral portion 122.
The inner journal sleeve 124 and the inner journal integral portion 122 are joined at their interface by the inner journal bond layer 125. The interface may be at the inner surface of the inner journal sleeve 124 and the outer surface of the inner journal integral portion 122 when the inner journal sleeve 124 is located around the inner journal integral portion 122 prior to forming the inner journal bond layer 125.
The inner journal bond layer 125 may be a metallurgical bond formed by an exothermic reaction ignited between the inner journal integral portion 122 and the inner journal sleeve 124. The inner journal bond layer 125 metallurgically bonds at least a majority of the interface between the inner journal sleeve 124 and the inner journal integral portion 122 together, such as joining at least a majority of the inner surface of the inner journal sleeve 124 and at least a majority of the outer surface of the inner journal integral portion 122 together. Some residual material from the exothermic reaction may remain after the formation of the inner journal bond layer 125. In the embodiment illustrated in
Cam sleeve 134 is located outward from and surrounds the cam integral portion 132. The cam sleeve 134 may be hollow and include a constant thickness. The thickness may be within a predetermined tolerance. The cam sleeve 134 may also include multiple cam sleeve sections 136. In the embodiment illustrated, the cam sleeve 134 includes two cam sleeve sections 136 that are combined to form the full profile of the cam 130. The cam sleeve sections 136 may split the cam 130 down the centerline of the cam 130 or may split the cam 130 in other locations. The cam sleeve sections 136 each include two cam sleeve ends 138. The cam sleeve sections 136 may be bonded together, such as by welding or by an exothermic reaction, at their adjoining cam sleeve ends 138. In some embodiments, the bonding of the cam sleeve sections 136 is adjacent the outer surface of the cam sleeve 134 and does not penetrate to the cam integral portion 132. The cam sleeve sections 136 may be symmetrical and may be split down the center of the cam sleeve 134. In the embodiment illustrated, the cam sleeve ends 138 extend between the outer and inner surfaces of the cam sleeve 134 normal to both the outer and inner surfaces.
The outer profile of the cam sleeve 134 is at least as large as the desired minimum material condition of the cam 130. Prior to being bonded to the cam integral portion 132, the inner profile of the cam sleeve 134 may be within a predetermined tolerance of the outer profile of the cam integral portion 132.
The cam sleeve 134 and the cam integral portion 132 are joined at their interface by the cam bond layer 135. The interface may be at the inner surface of the cam sleeve 134 and the outer surface of the cam integral portion 132 when the cam sleeve 134 is located around the cam integral portion 132 prior to forming the cam bond layer 135.
The cam bond layer 135 may be a metallurgical bond formed by an exothermic reaction ignited between the cam integral portion 132 and the cam sleeve 134. The cam bond layer 135 metallurgically bonds at least a majority of the interface between the cam sleeve 134 and the cam integral portion 132 together, such as joining at least a majority of the inner surface of the cam sleeve 134 and at least a majority of the outer surface of the cam integral portion 132 together. Some residual material from the exothermic reaction may remain after the formation of the cam bond layer 135.
Main journal sleeve 214 is located outward from and surrounds the main journal integral portion 212. The main journal sleeve 214 may include a hollow cylinder shape and may include multiple main journal sleeve sections 216. In the embodiment illustrated, the main journal sleeve 214 includes two main journal sleeve sections 216 that are combined to form the hollow cylinder shape. The main journal sleeve sections 216 each include two main journal sleeve ends 218. The main journal sleeve sections 216 may be bonded together, such as by welding or by an exothermic reaction, at their adjoining inner sleeve ends 128. In some embodiments, the bonding of the main journal sleeve sections 216 is adjacent the outer surface of the main journal sleeve 214 and does not penetrate to the main journal integral portion 212. The main journal sleeve sections 216 may be symmetrical and may be split down the center of the main journal sleeve 214. In the embodiment illustrated, the main journal sleeve ends 218 extend between the outer and inner surfaces of the main journal sleeve 214 at an angle relative to a surface normal to both the outer and inner surfaces, and are not normal to the outer and inner surfaces of the main journal sleeve 214.
The outer profile, such as the outer diameter, of the main journal sleeve 214 is at least as large as the desired minimum material condition of the main journal 210. Prior to being bonded to the main journal integral portion 212, the inner profile, such as the inner diameter, of the main journal sleeve 214 may be within a predetermined tolerance of the profile of the main journal integral portion 212.
The main journal sleeve 214 and the main journal integral portion 212 are joined at their interface by the main journal bond layer 215. The interface may be at the inner surface of the main journal sleeve 214 and the outer surface of the main journal integral portion 212 when the main journal sleeve 214 is located around the main journal integral portion 212 prior to forming the main journal bond layer 215.
The main journal bond layer 215 may be a metallurgical bond formed by an exothermic reaction ignited between the main journal integral portion 212 and the main journal sleeve 214. The main journal bond layer 215 metallurgically bonds at least a majority of the interface between the main journal sleeve 214 and the main journal integral portion 212 together, such as joining at least a majority of the inner surface of the main journal sleeve 214 and at least a majority of the outer surface of the main journal integral portion 212 together. Some residual material from the exothermic reaction may remain after the formation of the main journal bond layer 215.
The main journal sleeve 214 may need to be aligned in a predetermined orientation relative to the main journal integral portion 212 to align selected features of each.
Referring to
Referring to
The main journals 210 and the rod journals 220 may be joined by webs 230. The main journal integral portions 212 and the rod journal integral portions are integral to the webs 230 and to each other. The mounting flanges 240 may be located at each end of the crankshaft 200.
A shaft for a machine, such as a construction or a mining machine, in accordance with the invention disclosed herein includes at least one contact feature. The contact feature may include the end journal 110, the inner journal 120, the cam 130, the main journal 210, or the rod journal 220. The contact feature includes an integral portion and a sleeve. The integral portion may include any combination of the features described herein relative to the end journal integral portion 112, the inner journal integral portion 122, the cam integral portion 132, and the main journal integral portion 212. The sleeve includes at least one sleeve section and may include multiple sleeve sections. The sleeve may also include any combination of the features described herein relative to the end journal sleeve 114, the inner journal sleeve 124, the cam sleeve 134, and the main journal sleeve 214.
In embodiments, not all contact features include an integral portion and a sleeve. Some contact features of the shaft may only include an integral portion with no sleeve. In other embodiments, all contact features include an integral portion and a sleeve.
The material of the sleeve may be selected based on the desired contact properties at the outer surface of the contact feature, such as the hardness. The sleeve includes materials capable of bonding to the integral portion. In some embodiments, the sleeve includes the same or a similar material as the material of the integral portion. In other embodiments, the sleeve includes materials that are different than the materials of the integral portion. Further, the sleeve may have a surface treatment applied prior to being bonded to the integral portion. The sleeve may include any metal including, inter alia, steel, tool steel, nickel alloys, and bronze.
Contact features for shafts of machines, such as construction and mining machines, may be subject to various stresses, strains, and various forms of wear. The amount of wear on each contact feature may be based on the location of the contact features, which components of the machine are connecting to or contacting the contact features.
The method includes placing a sleeve around the integral portion at step 804. Step 804 may include aligning the sleeve with the integral portion. In some embodiments, the integral portion and the sleeve include features, such as holes and passages that need to be aligned. Aligning the sleeve with the integral portion may include mating one or more alignment features, such as the integral portion alignment feature 209 and the sleeve alignment feature 208. In some embodiments, aligning the sleeve with the integral portion is performed using an alignment aid to align the features of the sleeve and the integral portion. In embodiments, the alignment aid is an alignment dowel that locates the sleeve relative to the integral portion, such as by placing the alignment dowel in the oil hole and oil passage. The alignment aid may remain during the bonding step and may be removed after the bonding step is completed.
In embodiments, the sleeve is placed around the integral portion with an interference fit. These embodiments may include a sleeve that is formed of a single integral piece.
The method also includes placing a reaction material between the sleeve and the integral portion at step 806. Step 806 may include applying the reaction material to the inner surface of the sleeve or applying the reaction material to the outer surface of the integral portion prior to placing the sleeve around the integral portion. Applying the reaction material to the inner surface of the sleeve or to the outer surface of the integral portion may include coating the surface with a layer of the reaction material. Placing the sleeve around the integral portion may simultaneously place the reaction material between the sleeve and the integral portion when the reaction material has already been applied to either the inner surface of the sleeve or the outer surface of the integral portion.
The method further includes bonding the sleeve to the integral portion using the reaction material at step 808. Step 808 may include bonding at least a majority of an interface between the integral portion and the sleeve together. Step 808 may also include initiating an exothermic reaction in the reaction material. The exothermic reaction may be initiated electrically, thermally, or mechanically. In some embodiments, an electricity source, such as a battery, or an arc welder, provides an electrical charge the supplies the energy to initiate the exothermic reaction. In other embodiments, a heat source, such as a soldering iron, provides the heat that supplies the energy to initiate the exothermic reaction. In yet other embodiments, mechanical energy supplies the energy to initiate the exothermic reaction, such as by striking the material physically.
Once initiated, the exothermic reaction may self-propagate and generate enough heat to bond the sleeve and integral portion together. The exothermic reaction may cause the bond without causing enough heat to significantly affect the properties of the sleeve and the integral portion. Step 808 may bond a majority of the interface between the sleeve and the integral portion together, such as bonding the inner surface of the sleeve to a majority of the outer surface of the integral portion. The bond may be strong enough to withstand the stresses and strain in the journal caused during contact with other components of the machine. The bond may be able to withstand stresses and strains to prevent rotation between the integral portion and the sleeve in situations where an interference fit between a journal and a sleeve may not be sufficient to prevent independent rotation of the sleeve relative to the journal. In some embodiments, the reaction material may include, for example, thermite, a mixed powder of iron oxide and aluminum, or metals that can have an intermetallic reaction, such as nickel and aluminum.
The method may further include post-machining the sleeve after bonding the sleeve to the integral portion at step 810. Step 810 may include machining the sleeve to a desired profile of the journal, the desired profile being within the dimensional requirements of the journal.
In some embodiments, the method includes surface treating, such as heat treating or cold working, the sleeve. The surface treatment may be performed before or after steps 806 and 808. Surface treating, such as heat treating, the sleeve prior to steps 806 and 808 may allow for the modifying of the material properties of the sleeve without affecting the material properties of the remainder of the shaft. This may allow for a shaft that includes multiple journals to have journals with different surface treatments and different properties. Journals with different properties can also be accomplished by using journals of different materials.
In some embodiments, the sleeve includes multiple sleeve sections. The method may include forming a closed loop of the sleeve sections around the integral portion and bonding the sleeve sections together. In some embodiments, bonding the sleeve sections together may include a bonding process that uses an external heat source, such as welding. The welding may initiate the exothermic reaction. In other embodiments, the reaction material is also placed between the adjacent ends of the sleeve sections and the exothermic reaction also bonds the sleeve sections together. The multiple sleeve sections facilitate placing a sleeve around an integral portion that could not otherwise receive a sleeve due to its location on the shaft.
The process illustrated in
The preceding detailed description is merely exemplary in nature and is not intended to limit the invention or the application and uses of the invention. The described embodiments are not limited to use in conjunction with a particular type of machine. Hence, although the present disclosure, for convenience of explanation, depicts a rotating shaft for a construction or mining machine, it will be appreciated that the rotating shaft in accordance with this disclosure can be implemented in various other configurations and can be used in other types of machines. Furthermore, there is no intention to be bound by any theory presented in the preceding background or detailed description. It is also understood that the illustrations may include exaggerated dimensions to better illustrate the referenced items shown, and are not consider limiting unless expressly stated as such.
